Atmospheric carbon dioxide and its stable isotope ratios, methane, carbon monoxide, nitrous oxide and hydrogen from Shetland Isles

• Published in: Atmospheric environment (1994) Vol. 32; no. 19; pp. 3331 - 3338
• Main Authors: Francey, R.J., Steele, L.P., Langenfelds, R.L., Allison, C.E., Cooper, L.N., Dunse, B.L., Bell, B.G., Murray, T.D., Tait, H.S., Thompson, L., Masarie, K.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-1998
• Subjects: Atmospheric composition; latitudinal gradient; network integration; ocean sink; trace gases; ANE, British Isles, Scotland, Shetland Is; Shetland Isles, Scotland; Atmospheric composition; network integration; ocean sink; trace gases; latitudinal gradient
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(97)00491-3

Since November 1992, 0.5
l
glass flasks have been filled approximately monthly with dry marine air from Shetland Isles, Scotland (60.2°N, 1.2°W) and transported to CSIRO, Australia for analyses. The Shetland site is part of a CSIRO global flask network with 10–12 sites, anchored to continuous high precision
in situ measurements made at the Australian Cape Grim Baseline Station (40.7°S, 144.7°E), a primary station in the Global Atmosphere Watch programme (GAW) coordinated by the World Meteorological Organisation. The methodology is summarised, and Shetland results for CO
2, CH
4, N
2O, CO, H
2 and
δ
13C,
δ
18O of CO
2 presented for the period 1992–1996. We compare data to available results from surrounding stations of the NOAA cooperative network (in particular Mace Head, Ireland, 53.3°N, 9.9°W), and address issues of both trace species intercalibration and atmospheric spatial gradients. While considerable uniformity of trace-gas composition is evident in oceanic air over a 13° range of latitude, nevertheless anomalies in CO
2 concentration and isotopic composition are suggested in samples representing air to the west of Shetland. The potential for remotely monitoring integrated emissions from northern Europe is also identified.